INTRAVENTRICULAR GALANIN IMPAIRS DELAYED-NONMATCHING-TO-SAMPLE PERFORMANCE IN RATS

Galanin is a neuroactive peptide that coexists with acetylcholine in t he basal forebrain region. Galanin inhibits cholinergic functions in v itro and in vivo and has been shown to impair performance in some memo ry tasks. The present study compared the effects of galanin with the e ffects of scopolamine (a muscarinic antagonist) and ketamine and MK-80 1 (both NMDA receptor antagonists) on performance of an operant, spati al, delayed nonmatching-to-sample task in rats. Choice accuracy was im paired in a dose-dependent but delay-independent manner by galanin, sc opolamine, and MK-801 but was not systematically influenced by ketamin e. Measures of session duration, trials completed, discrimination accu racy, perseveration, within-trial error distribution, and operant leve r pressing were also analyzed. These results support observations that galanin disrupts performance in memory tasks requiring delayed respon ding but that the disruption is not specific to mnemonic capabilities.